"This is something I never really made much of or told anyone about, but for me, at least, Miracle Monday is a real holiday. In the book it's the third Monday of every May. On that day, according to the book, resort owners on the glaciers of Uranus raise ski-lift tickets for the influx of tourists. Teamsters driving slow-moving cargo transports to Earth from mining operations in the asteroid belt get drunk and silly like sailors crossing the Equator for the first time. In honor of Superman's chosen profession, even journalists can spend the holiday with their families. There are laughter, reflection, public celebration with barbecues and holographic light shows all over the solar system, merriments of all sorts. It's a big holiday.
As it happens, here in the real world, I received my first copy of Superman: Miracle Monday in the mail from my editor at Warner Books on May 18, the third Monday in the month of May, 1981. It was a special day, totally coincidental, and I've never really told anyone that before. Considering what Superman did in the book on that day, it was a holiday worth celebrating for a long time, so along with my birthday, Einstein's birthday and the first day of summer, Miracle Monday is a day that I will probably continue to set apart."